The present invention relates to a power steering mechanism for vehicles, in particular motor boats, with a control wheel, a cable that is to be attached thereto having a core and a sheath, and a lever system which is connected to the core and is drive-connected to the control of the vehicle or motor boat. The sheath of the cable is braced at the control means wheel and is attached to an adjustable control member of a control valve, which controls a hydraulic operating cylinder, whose power piston also acts on the lever system.
A power steering mechanism of this kind disclosed in U.S. Pat. No. 4,295,833. The control wheel is connected via a swivel lever to the core of the cable whose sheath is clamped immovably in the region of the control wheel. At the other end, the core is connected to the lever system of the control, whereas the sheath of the cable is connected to the adjustable control member of the control valve. In this known design the cable acts on a private operating system for the control valve separated from it. The operating cylinder is also separated from the control valve. To connect the separated control systems, they must have their own pressure medium lines, which can be damaged and lead to stoppages. The cable and power piston require their own lever system. The known power steering mechanism is, therefore, expensive and bulky, and needs a relatively large space which is often not available, especially on motor boats.
A power steering mechanism of this kind is also known in which the control valve and the operating cylinder are built parallel to one another in a common housing, wherein the core of the cable pierces the control member of the control valve axially and is attached to an operating linkage for the control. In this manner a separate system to actuate the control valve can be dispensed with. For servo support by means of the operating cylinder, however, this known device needs its own operating linkage.